Spinal 5-HT2A receptor is involved in electroacupuncture inhibition of chronic pain.

Knee osteoarthritis (KOA) is a highly prevalent, chronic joint disorder, and it is a typical disease which can develop chronic pain. Our previous study has proved that endocannabinoid (2-AG)-CB1R-GABA-5-HT pathway is involved in electroacupuncture (EA) mediated inhibition of chronic pain. However, it is still unclear which among the 5-HT receptor subtype is involved in EA evoked 5-HT mediated inhibition of chronic pain in the dorsal spinal cord. 5-HT2A is a G protein-coupled receptor and it is involved in 5-HT descending pain modulation system. We found that EA treatment at frequency of 2 Hz +1 mA significantly increased the expression of 5-HT2A receptor in the dorsal spinal cord and intrathecal injection of 5-HT2A receptor antagonist or agonist reversed or mimicked the analgesic effect of EA in each case respectively. Intrathecal injection of a selective GABAA receptor antagonist Bicuculline also reversed the EA effect on pain hypersensitivity. Additionally, EA treatment reversed the reduced expression of GABAA receptor and KCC2 in the dorsal spinal cord of KOA mice. Furthermore, we demonstrated that intrathecal 5-HT2A receptor antagonist/agonist reversed or mimicked the effect of EA up-regulate of KCC2 expression, respectively. Similarly, intrathecal injection of PLC and PKC inhibitors prevented both anti-allodynic effect and up-regulation of KCC2 expression by EA treatment. Our data suggest that EA treatment up-regulated KCC2 expression through activating 5-HT2A-Gq-PLC-PKC pathway and enhanced the inhibitory function of GABAA receptor, thereby inhibiting chronic pain in a mouse model of KOA.

Exploring NFκB pathway as a potent strategy to mitigate COVID-19 severe morbidity and mortality.

The pandemic of coronavirus disease 2019 (COVID-19), for which there does not appear to be an approved cure, the primary treatment options consist of non-pharmacological preventive measures and supportive treatment that are aimed at halting the progression of the disease. Nuclear factor kappa B (NFkB) presents a promising therapeutic opportunity to mitigate COVID-19-induced cytokine storm and reduce the risk of severe morbidity and mortality resulting from the disease. However, the effective clinical application of NFkB modulators in COVID-19 is hampered by a number of factors that must be taken into consideration. This paper therefore explored the modulation of the NFB pathway as a potential strategy to mitigate the severe morbidity and mortality caused by COVID-19. The paper also discusses the factors that form the barrier, and it offers potential solutions to the various limitations that may impede the clinical use of NFkB modulators against COVID-19. This paper revealed and identified three key potential solutions for the future clinical use of NFkB modulators against COVID-19. These solutions are pulmonary tissue-specific NFkB blockade, agents that target common regulatory proteins of both canonical and non-canonical NFkB pathways, and monitoring clinical indicators of hyperinflammation and cytokine storm in COVID-19 prior to using NFkB modulators.